Batteries are essential for the portability of wireless terminals, for example cellular phones and other portable communication devices. The Subscriber Information Module (SIM) card is a programmable card in cellular phones, which stores all of a cell phone subscriber's personal information and phone settings. Battery removal detection in a cellular phone is a part of the battery interface in a cell phone because the SIM card needs to be powered off in controlled manner to be able to avoid being permanently damaged. In case of a sudden battery removal, a fast indication of battery removal to the SIM interface is needed because the SIM interface may loose power rapidly after battery removal. Recently cell phone batteries have included circuitry to identify the battery type, sense battery temperature, and store other related information. Temperature sensing, among other features, requires the ability of the cell phone to engage in data communication with the battery pack.